Heretofore the prior art has proposed various forms or types of electrical switches which were responsive to the level (height or elevation) of a monitored liquid. For the most part such prior art switches may be considered as being of two types.
For example, one of such types would comprise switches employing a float which, upon being buoyantly moved upwardly by the monitored fluid, would apply a force as against a normally open (or closed) switch arm causing such switch arm to be moved to a closed (or open) position. In this type of prior art switch, the act of switch closure (or opening) is somewhat irregular in action since such closure (or opening) movement is related to the speed of change in fluid level and consequently there may be an occurrence of an unstable making and breaking of the associated electrical circuit prior to such switch being placed into a stable electrically closed (or open) condition.
The other type of prior art switch would comprise switches employing a float which, in turn, carries a bridging-like electrical conductor so that upon being moved by the monitored fluid the bridging-like conductor would engage related stationary electrical contacts or terminals of an associated electrical circuit thereby closing such electrical circuit. This type of prior art switch also exhibits an irregular electrical closing action with occurrences of unstable making and breaking of the associated electrical circuit prior to such switch being placed into a stable electrically closed (or open) condition.
Further, in such prior art switches, it is often accepted practice to have the various elements, such as contacts, switch arms, and/or bridging contacts, exposed to the liquid being monitored with such exposure permitting at least the vapor of the monitored liquid and even splashing of the monitored liquid to come into contact with such electrically conductive switching elements. This, in turn, often causes a corrosive action on such switching elements resulting in switch failure or at least unreliable switch operation.
Accordingly, the invention as herein disclosed is primarily directed to the aforestated as well as other related and attendant problems of the prior art.